zero2sixd

I'm looking for advice on the effectiveness of ducting the stock S197GT brakes using one of the available kits (Agent 47, V8 Power, etc.) vs. spending more money on new calipers and 14" rotors (Brembo, StopTech, Baer, etc.).

I should start up front by saying that I am already using the Hawk HP+ pads, ATE Super Blue brake fluid and (shhhh don't tell my F Stock competitors) stainless braided brake lines. My use of the car is primarily for autox (7-8 per year) and track events (1-2 year) with very little street use other than driving to/from said events. Autox is not very hard on brakes, at least as it concerns overheating and fade, but the track events are murder on the stock brakes. My experience on the track has been that, above everything else on the car, the brakes are the weak point.

The autox use complicates things slightly since I will be bumped out of F Stock with either of the above brake solutions into either STX if I use the brake ducts or STU if I use larger rotors/new calipers. The latter statement I make primarily because I am assuming a wheel wider than 8" to clear the calipers, which bumps you out of STX.

The scientist in me really wants to try the ducts to prove that this effective and cheap but I don't want to put money into that, only to find that the stock brakes are still inadequate. So, long-story-short, has anybody else with my same issues done this before, or have experience with this sort of thing? And, what were your results on the track? No fade? Some fade?

jayel579

Yaknow the F-Stock national champ posts on here right?

You sound like me with what you use your car for. I mainly use mine at autoX events but I am stepping up to come track events this year and will continue to do so. RodeoFlyer swears by air ducs, shoot him a PM if you want to get his advice. I have been considering adding in the air ducs also then just taking them out when I autoX. I will be changing my tires when I get to the track, the air ducs aren't that hard to just pull out while I am in there. I doubt running locally anyone will give you a hard time. You might want to step up to a more agressive pad at the track, like a DTC -60. I know the HP+'s you can use on the street but the DTC-60's you can't. That might help eliminate some fade for you but also plan on replacing your rotors more often.

.boB

You really have to evaluate your problem before making any changes.

The purpose of air ducts is to force more air through the rotor to keep it cool. I don't autocross, I road race. I am definatly going to see improvements with cooling ducts because I hit speed of 145mph, and brake hard and often for 20-30 minutes at a time. That builds up a lot of heat. But an autocross run is what, 1:30? do your brakes really get that hot? I would put some heat detector paint on the rotor and caliper to find out.

With that same thought, my brake pads work better at a higher temp. The work really good on the street when they're cold. But when they get hot on the track they work better. Do your pads even get hot enough to operate in their range? The HP+ pads should be the perfect choice, but I would check temps to be sure.

So, if testing shows that the brakes get too hot, then add cooling ducts. If not, then go to a bigger rotor.

Argonaut

Wow - are you really experiencing brake fade running HP+ (albeit a street pad) and ATE superblue? What track are you running on? I'm planning on running at Pocono next month with HT10s in front, ATE and SS lines. I'll see how that does before I consider ducts. Personally bigger brakes would be my last choice - their cost is unreal and you have to have 18" or bigger wheels. You can read past posts from RodeoFlyer talking about stock calipers and rotors being user at national level competition.

Sleeper_08

Anotheralternative for the brake cooling are the Quantum Motorsports kits. Mine just arrived today and the quality is excellent.

http://www.quantummotorsports.com/05....htm#RaceBrake

http://www.quantummotorsports.com/05mustanginlet.htm

Import_Slaya

Don't waste your money on the 14" kit--they just are not necessary and their increase in performance is arguable when you take in to consideration the extra mass of not only the brakes/rotors, but the wheels needed to clear them. I won't even get into the cost differences in running 18" performance tires vs. 17" performance tires, or rotors. They do look blingtastic, though.

If you open track, I would say you absolutely need brake ducts, however. I use the Agent47 kit, but there are plenty of other options that are much less expensive.

The stock brakes are actuallyquite niceonce you upgrade the pads and fluid, and run ducts. I swear by EBC Yellowstuff pads as a great compromise track/street pad. I've yet to experience fade with them on the track (using ducts), and they are very streetable--but dusty! Upgrading the lines to stainless won't really get you a noticable performance increase, but it does give you peace of mind. Nothing worse than losing a brake line at 130 MPH.

zero2sixd

Yep, I really am. I should probably state that I have attended racing "schools" (Skip Barber, Jim Russell) and done quite a bit of karting before ever having a car I would actually take to the track and while that doesn't make me very good, it does give me quite a bit of experience with threshold braking, trail braking, etc. All this is to say, I was not taking it easy on the brakes. I have been to Thunderhill in NorCal twice now (both times with the Super Blue, HP+ and SS lines) and the experience went something like this with my 20 minute sessions:

Day 1
Session 1: Wow, that was fun, can't wait to get back out there. Tires (OEM G-Force KDWS) doing better than expected and I didn't crash!
Session 2: Sweet, tires making more noise now, and I didn't crash!
Session 3: Tires really howling now, corner entry/exit speeds increasing, passing everyone else in my "newb" class, and I didn't crash!
Session 4: I'm really getting the hang of this now, wait a minute...not...stopping....now, move brake point back
Session 5: Brake point moved way back, just taking it easy now, not having as much fun

Day 2
Session 1: Same as session 3 above, except I'm no longer in the "newb" class
Session 2: Same as session 4 above

Thunderhill has a particularly punishing series of corners in succession:

Turn 9, 10, 11 and 14. The problem is that there is no rest for the brakes until after turn 14 when you round 15 back out onto the front straight. When I experience fade, it's always at turn 14. What I'm trying to illustrate with the session info above is that, as my driving and line improve I arrive faster and faster into the braking zones. Now, I could just keep moving the brake point back as I experience fade, but it's not in my nature (nor for many other people in this forum, I expect). Also, I'm not hitting the ABS, so I still feel like the problem is (lack of) heat dissipation.

Sleeper_08

From my research it sounds like brake cooling would be the thing to try. On a fast track like the brakes get to cool but on a short track or one with a series of tight corners that doesn't happen.

The price for the cooling kit, about $250 with inlets,is a lot less than for the brakes, about $1500 for the GT500 kit, so you might want to try the cooling kit first to see if it makes a big improvement.

In my case I've opted for both as some of the tracks around here are pretty short and with the SC we expect that it will be really hard on the brakes.

On May 19 we'll find out!

houstonnw

I have a stock suspension '07 GT and when I upgraded from the all-season tires to Kuhmo SPT's I got into serious brake fade, even on a cold damp morning at Texas World Speedway. I don't know about autocross rules, but I've gone to Carbotech XP10 fronts and XP8 rear pads for HPDE's. I use the Bobcat pads for the street. The reason I chose Carbotech is that you can use the same rotors with all of their pads, so I simply change out the pads for track days.

At TWS in early March I asked my instructor, who races in American Iron, to drive my car. He didn't see any brake fade and commented about how good the brakes were.

The XP10/XP8 combo seem grabby on the way to the track, so I don't think that they need a lot of heat to work properly.

Now my experience was in January and March, talk to me again in July or August and I might be telling you about my new brake ducts!

F1Fan

Hi zero2sixd,

It's not thebrakes that stop your car it's the tires. All brakes do is convertthe car'smotion into heat through friction and then hopefully shed that heat before you need to use the brakes again. Bigger brakes can do nothingto improve your single-stop stopping distances and can in fact be the cause of increased stopping distances if not well designed and balanced for the existing brake system. I've been postinghereexplaining tofolksfor yearsthatgoodbrake cooling is more important than sheer brake rotor size and mass than a big brake kit for high-perfomance street and road courseuse.Before I had an S197GT I used to tell my people the same thing for certain model Porsches and BMW's. Of course some model carscan really use upgraded brake calipers, rotors andmaster cyclinders in addition tobrake ductsbut that's another story.

All it takes as you have figured out is adding aset ofspindle mounted ducts with a nice length of3" brake duct hose and nose ducts in the lower grill over and above the usual brake upgrades. Combine a goodspindle mounted brake cooling systemwith the usual upgraded S.S. brake lines, racing brake fluid, pads with the appropriate MOT and operatingtemp rangefor your use and acomplete brake system fluid flushand youwill have brakes that stop just as well as any big brake kit and have several advantages over a BBK to boot. The biggest advantagestoinstallingspindle mounted brake cooling ducts and upgraded stock sized brake components over the typicalbig brake kitare:much more resistant to fade, much faster recovery from overheatedpads & rotors,much lower chance of boiling brake fluid (big no-no, boiled fluid is useless fluid),improved pad and rotor life,lower weight (gives improved grip, handling and ride)than typicalBBK, lower inital cost than BBK, lower lifetime costs then BBK.

I did this work on my ownS197GT long ago.In theensuing years I havealso installed aBaer GT Plus kit with 14" 2-piece rotors andto be sure the larger GT Plus brakeshave aslightly higher inital bite when cold and seem to be nearly fade freeunder all but the most brutal of road course conditions. But I can also confirm through personal experience that youwill be perfectly happy with theway a well upgraded S197GT brake system works if you have installedspindle mounted ducts and the previously mentioned core brake system upgrades.I know that spending over $1,000 for what appears to be just a stock brake system might seem a little wacky but trust me it is money well spent when compared to the performance returns ofa big brake kit at even the sameprice.

Does this help?

HTH!